The Government and casino operators Sky City are understood to have finalised a deal on Auckland's $402 million convention centre.

Two previous deadlines to sign off the deal have been missed but the deal was done late this evening.

The international convention centre will be funded by SkyCity in exchange for widely-criticised gambling concessions.

Final details of the deal are expected to be unveiled tomorrow morning.It will need legislation, which is expected to have a fiery passage through Parliament.

Under details previously announced SkyCity will pick up the construction, land and fit-out costs, and in return be allowed an extra 230 poker machines and another 40 gaming tables as well as an extension of its license until 2048.

The convention centre will cater for up to 3500 people with construction to begin next year ahead of a 2017 opening.

SkyCity will operate the centre for at least 35 years.

The convention centre was expected to give the economy a $90m annual injection and create 800 ongoing jobs.